Water and other non-carbonated beverages, and particularly sports drinks, are sold in individual servings in the form of deformable plastic bottles which are squeezable. Such bottles typically have caps in the form of a pull open/push close type closure, which typically provides a single fluid passage which is not vented. The lack of a vent in the closure causes the deformable container to collapse as a consumer draws a beverage from the container while drinking, due to a pressure differential that is created between the fluid and the exterior of the container, since the external pressure is higher as the exiting liquid causes the internal pressure to decrease. At some point during the drinking process, depending on the size of the container, no additional liquid can be withdrawn from the container until the pressure is equalized by stopping the drinking process and allowing air to rush in through the single fluid passage in the closure. This equalization can cause a reflux or backwash from the consumer's mouth into the container, which tends to contaminate the fluid in the container. Because of these problems, consumers frequently equalize pressure by holding the bottle away from the mouth and squeezing the deformable bottle in a series of squirts, with pressure equalization taking place between each squirt. This procedure often results in spills of the fluid, and results in the consumer drinking less than were it easier to dispense fluid. The lack of a vent in these closures also limits the freedom of design and materials for the container due to the fact that the deformable container must be able to collapse.
Conventional fluid containers are sometimes vented, but the vent typically is part of the container itself, and not part of the closure. Vented closures intended for pouring are known, but are undesirable for use in non-pouring type closures in which fluid will not continuously pour out of the bottle when the bottle is tilted downwardly. Sports bottles are an example of a non-pouring type closure which are intended to be left open for quick drinks during an activity, and can be easily knocked over. Furthermore, most pouring-type closures require the user to hold the container with particular orientation, often with the spout oriented downwardly for pouring, and such pouring closures are not suitable for sports bottles or the like in which the user may raise the closure without regard to any particular orientation to the closure. In general, pouring type closures are not suitable for sports bottles and other deformable containers in which the liquid exits in spurts due to squeezing of the container and/or placing the user's mouth around the closure opening to draw liquid out of the container.
Other non-pouring type closure systems have utilized a flap valve or diaphragm to regulate the equalization pressure and/or prevent liquid from leaking through vent passages for the closure. The additional components and assembly processes required to incorporate a flap valve or diaphragms or washers in a closure adds prohibitive expense and complexity to the closure. Containers designed for the application of drinking while moving are designed to allow the user to drink without tilting the head back. Such devices may use a straw to draw liquid from the bottom of an essentially rigid container and operate similar to a pouring-type container. Further, such devices may use a flap valve or other complex mechanism to vent the rigid container. Such approaches are not suitable for a standard beverage container and add prohibitive expense and complexity to the closure.
The manufacturing cost of closures used on sports drink containers and the like is critical. An increase of fractions of one cent can severely impact marketability by the closure manufacturer since consumers usually are focused on the sports beverage or supplier and are generally unwilling to pay more for the bottle and closure which contains the beverage. Likewise, it is very important that any closure should be compatible with existing bottling and assembly equipment and should be usable in connection with standard bottling and assembly processes. The types of closures proposed in the past have been incompatible with these requirements.
One objective of the present invention is to provide an improved vented fluid container closure of the non-pouring type that is adaptable to a standard beverage container.
It is another objective of the present invention to provide fluid container closures that are readily manufactured using molding and other equipment currently used for beverage container closures and which are easily adaptable to current beverage filling and processing equipment.
It is a further objective of the present invention to solve the problem of contamination of fluid while drinking due to reflux in a squeezable plastic container which dispenses liquid in squirts when held overhead in no particular orientation.
It is yet another objective of the present invention to provide improved push-pull type closures and improved flip-top rotatable type closures that allows drawing of fluid out of containers and provide new closure features adaptable to standard beverage filling and processing equipment.
It is still another objective of the present invention to provide a liquid closure that is vented to air and has vent passageways that self-seal using the surface tension of liquid in direct liquid contact with one or more vent apertures and which eliminates valves, flaps and other sealing mechanisms.